The story begins with Merlina participating in a science fair, where she uses her uncle Lucas as a test subject and reveals she's been studying the genes of his pet octopus, Socrates. Later, a lawyer arrives with a claim that Merlina was switched at birth. The family embarks on a vacation, but the lawyer follows them. Meanwhile, Merlina performs a paternity test on herself and discovers she may not be the Addams Family's biological daughter. She sets out to uncover the truth, meeting the scientist who claims to be her real father. However, she soon discovers his true intentions: to create hybrid soldiers by combining human and animal DNA. Merlina refuses to comply and, with the help of her family, defeats the scientist and saves her family from his experiments. In the end, Merlina returns home and forgives her parents, and the family welcomes her back with open arms.
Here are the extracted facts:
1. The story begins at a school science fair where Berlin is participating.
2. Merlina is using her uncle Lucas as a test subject for an experiment.
3. Lucas tells Merlina about the genes of his pet octopus, Socrates.
4. A hologram of a famous scientist announces the winner of the science fair.
5. All participants are declared winners for trying.
6. Merlina is not present to accept her award.
7. A scientist offers to help Merlina with her research using his resources.
8. Merlina refuses the offer, citing a family secret.
9. Merlina uses a voodoo doll to hurt her brother Pericles.
10. Lucas gives Pericles a book on seduction.
11. The family receives a message from their daughter, warning them not to bother her.
12. Homer decides to take the family on a vacation to cheer up Merlina.
13. A lawyer named Mustela arrives, claiming to represent clients who believe Merlina was switched at birth.
14. Merlina's parents prefer not to tell her about the situation.
15. The family leaves for their vacation, with Morticia's mother in charge of Merlina's case.
16. The lawyer follows the family, accompanied by a bodyguard.
17. Uncle Lucas's inner octopus forces him to change direction towards Niagara Falls.
18. Pericles uses techniques from the seduction book to try and impress girls.
19. Merlina uses the voodoo doll to make Pericles dance and throw him into the falls.
20. The family escapes from the lawyer by throwing themselves into barrels and going over the falls.
21. Merlina's parents are approached by the lawyer again.
22. The family dresses up as cowboys to camouflage themselves.
23. Merlina participates in a talent contest, using her mind-reading abilities.
24. The lawyer arrives at the contest, but Merlina's disguise fools her.
25. Merlina throws paint on the participants to stop the contest.
26. The family escapes from the lawyer again.
27. The family arrives at the Grand Canyon, where Uncle Lucas's metamorphosis continues to advance.
28. Cousin Cosa leaves on a private plane and gives Merlina a necklace.
29. The family arrives at the beaches of Miami, where they meet up with Cousin Cosa.
30. The lawyer is not present, but the family soon discovers that he has been following them.
31. Merlina's parents accept an invitation to stay with a scientist who claims to be her real father.
32. The scientist reveals that he has been working on a project similar to Merlina's.
33. The scientist shows Merlina the results of a paternity test, which are positive.
34. Merlina's parents reveal to her that she is not their real daughter.
35. The scientist's wife and daughter, Ophelia, seem to be failed experiments with human traits.
36. The scientist wants to use Merlina's research to create hybrid soldiers and sell them to governments.
37. Merlina refuses to help the scientist, and he decides to activate the process himself.
38. The Addams family battles the scientist and his bodyguard.
39. The scientist is revealed to be a former cellmate of the Addams family's butler.
40. The experimental substance falls and mutates Ophelia into a pig.
41. The scientist is defeated, and Uncle Lucas is restored to normal using the DNA from Merlina's necklace.
42. Ophelia has managed to completely mutate a person using the experimental substance and love.
43. Merlina asks her parents for forgiveness and gives them a hug.
44. The family returns home and finds their grandmother in the middle of a party.
45. Merlina reveals that her hair is actually a toupee.